Drug & supplement interaction

Celery + Hydrochlorothiazide, Methyldopa

Hydrochlorothiazide, Methyldopa brand names: Aldoril 15, Methazide, Aldoril 25, Aldoril D30.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Hydrochlorothiazide, Methyldopa falls into 2 drug categories that Celery can interact with; the most serious is rated moderate. Theoretically, celery seed extract might have additive effects with antihypertensive drugs.

Read the full interaction report
SeverityModerate
LikelihoodProbable
Interactions2
EvidenceB
What do Severity, Likelihood & Evidence mean?
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Interaction report

Celery and Hydrochlorothiazide, Methyldopa

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

Celery interacts with whole categories of medication. Hydrochlorothiazide, Methyldopa falls into 2 of those categories, so it can interact with Celery in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

ANTIHYPERTENSIVE DRUGS

1 of 2

Why this applies to Hydrochlorothiazide, Methyldopa

Hydrochlorothiazide, Methyldopa falls under ANTIHYPERTENSIVE DRUGS — the group Celery interacts with.

Theoretically, celery seed extract might have additive effects with antihypertensive drugs.
Clinical research suggests that taking celery seed extract may reduce daytime systolic blood pressure by about 12 mmHg compared to less than 1 mmHg with placebo.
Severity Moderate Likelihood Probable Evidence B

Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports..

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the thing to keep in mind: your medicine combines hydrochlorothiazide (a water pill) and methyldopa, and both already work to lower your blood pressure. Celery seed extract appears to nudge blood pressure down too. In one study it dropped daytime systolic readings by around 12 points. So stacking the two could push your pressure lower than you want.

If your blood pressure drops too far, you might feel dizzy, lightheaded, tired, or faint when standing up. This isn't about a dangerous chemical clash, it's simply two things working in the same direction at once. Eating celery as food is very unlikely to matter. Before starting a concentrated celery seed supplement, please check with your pharmacist or doctor so they can keep an eye on your numbers.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Shayani Rad M, Moohebati M, Mohajeri SA. Effect of celery (Apium graveolens) seed extract on hypertension: A randomized, triple-blind, placebo-controlled, cross-over, clinical trial. Phytother Res 2022.
Minor

PHOTOSENSITIZING DRUGS

2 of 2

Hydrochlorothiazide, Methyldopa also falls under PHOTOSENSITIZING DRUGS.

Theoretically, celery might increase the risk of photosensitivity reactions when taken with photosensitizing drugs.
Laboratory research shows that celery contains photosensitizing agents such as phenols and psoralens.
Severity Minor Likelihood Possible Evidence D

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the simple version. Both pieces of this combo pill, the water pill hydrochlorothiazide and the blood pressure medicine methyldopa, can make your skin a little more sensitive to sunlight. Celery, especially as a concentrated seed extract or oil, contains natural compounds called psoralens that can do the same thing. Stacked together, the worry is that you might sunburn faster or break out in a rash after time outdoors.

The good news: this is rated minor and is mostly theoretical, based on lab findings rather than real patient reports. Eating celery as food is very unlikely to matter. If you take celery supplements, just use sunscreen, wear a hat, and check with your pharmacist if you notice your skin reacting more than usual.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Gral N, Beani JC, Bonnot D, et al. [Plasma levels of psoralens after celery ingestion]. Ann Dermatol Venereol 1993;120:599-603.
  2. Weber, I. C., Davis, C. P., and Greeson, D. M. Phytophotodermatitis: the other "lime" disease. J Emerg.Med 1999;17(2):235-237. PubMed
  3. Lombaert, G. A., Siemens, K. H., Pellaers, P., Mankotia, M., and Ng, W. Furanocoumarins in celery and parsnips: method and multiyear Canadian survey. J AOAC Int 2001;84(4):1135-1143. DOI
  4. Gorgus, E., Lohr, C., Raquet, N., Guth, S., and Schrenk, D. Limettin and furocoumarins in beverages containing citrus juices or extracts. Food Chem.Toxicol. 2010;48(1):93-98. PubMed
  5. Beier, R. C., Ivie, G. W., Oertli, E. H., and Holt, D. L. HPLC analysis of linear furocoumarins (psoralens) in healthy celery (Apium graveolens). Food Chem.Toxicol. 1983;21(2):163-165. PubMed

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Celery Also Interacts With Other Medications

Celery has 448 moderate, 202 minor known drug interactions in our database — the Hydrochlorothiazide, Methyldopa one above is among them. If you take anything else, check it against the full list below.

Moderate 448 Minor 202 No known interaction 2,180 (incl. Hydrochlorothiazide, Methyldopa)
Taking anything else?

Check Another of Your Medications Against Celery

Covers the 2,830 medications we’ve checked against Celery. Pick one to open its full report.

Everything else you take

See Every Supplement That Interacts With Hydrochlorothiazide, Methyldopa

This page covers Celery only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Hydrochlorothiazide, Methyldopa page lists 261 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), American Mistletoe (major), Asarabacca (major) and Beer (major).

By severity: 13 major · 223 moderate · 25 minor.

From our pharmacist’s overview on the Hydrochlorothiazide, Methyldopa page

“If you take hydrochlorothiazide with methyldopa (Aldoril, Methazide), this list deserves real attention, and the 13 major-rated entries are where to start. Most of the 261 ingredients either push blood pressure lower than intended or add to the diuretic effect, which can drain potassium.”

Reviewed by 2 · Jul 18, 2026

Open the Hydrochlorothiazide, Methyldopa interaction page

One more smart check

Taking Celery as Part of a Dietary Supplement Product? Check It for Interactions

We hold 1,687 real supplement products containing Celery, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Celery. Your product may carry other ingredients that interact with Hydrochlorothiazide, Methyldopa too, on top of Celery — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Celery and Hydrochlorothiazide, Methyldopa Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Celery
Top 25%

#168 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Hydrochlorothiazide, Methyldopa
Top 25%

#504 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Supplement

About Celery

What is Celery?

Celery
  • High blood pressure
  • Fluid retention (diuretic)
  • Joint pain and inflammation
  • Anxiety and sleep
  • Digestive support

Celery is a common vegetable that is also taken as a seed extract or oil supplement, mainly for blood pressure, fluid retention, and joint discomfort. Human evidence for these supplement uses is limited and mostly preliminary, so it should not replace proven treatments. Celery is generally safe as food, but concentrated supplements and possible allergic reactions warrant caution.

Read the full Celery monograph & all interactions
Keep checking

Other Drugs & Celery

Browse every other medication we’ve checked against Celery — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
448Moderate
202Minor
2,179No known interaction
448 Moderate 202 Minor 2,179 No interaction
Moderate

448 interactions

Showing 60 of 448 moderate interactions — see all 448 on the Celery page.

Minor

202 interactions

Showing 60 of 202 minor interactions — see all 202 on the Celery page.

No interaction 2,179 drugs checked — show the list

We also checked Celery against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,179 medications checked with no known interaction — see the full Celery list.

See the full Celery interactions page
See every supplement checked against Hydrochlorothiazide, Methyldopa, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Celery monograph › Uses, safety, and every drug interaction in one place Hydrochlorothiazide, Methyldopa supplement interactions › Every supplement checked against Hydrochlorothiazide, Methyldopa, ranked by severity Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Celery and Hydrochlorothiazide, Methyldopa Together: Common Questions

Can you take Celery with Hydrochlorothiazide, Methyldopa?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
Why are there 2 interactions listed for Celery and Hydrochlorothiazide, Methyldopa?
Hydrochlorothiazide, Methyldopa belongs to more than one drug category, and Celery interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Celery and Hydrochlorothiazide, Methyldopa interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Hydrochlorothiazide, Methyldopa and Celery?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.